The inventive subject matter relates to power distribution systems and methods and, more particularly, to systems and methods for power distribution in data processing environments, such as data centers and telecommunications facilities.
Modern data centers often use virtual machines (VMs), wherein multiple “virtual” servers may operate on a given physical server. These VMs may be migrated across servers to facilitate, for example, maintenance and/or replacement of hardware. Data centers often employ VM consolidation, in which VMs are assigned to a reduced or minimized number of physical machines. VM consolidation may also be used to reduce overall energy consumption in the data center.
UPS systems are commonly used in data processing environments such as data centers, medical centers and industrial facilities. UPS systems may be used in such installations to provide backup power to maintain operation of electronic equipment in event of failure of the primary utility supply.
A data center power distribution system may have a structure along the lines illustrated in FIG. 9. The power distribution system includes an automatic transfer switch (ATS) 30 that is configured to receive power from an input utility source 10 and from a generator 20. Downstream from the ATS 30 is a UPS 40, which may be used to condition power received from the ATS 30 and to provide backup power from a battery or other energy storage device in the event of a loss of power from the ATS 30. The output of the UPS 40 is coupled to a power distribution unit (PDU) 60 that, in turn, distributes power to loads 70. The loads 70 may include, for example, equipment racks that house servers, routers and other data processing devices.
Generally, the battery or other backup source for the UPS 40 may be used to maintain power from the UPS 40 to the PDU 60 until the generator 20 has been activated and the ATS 30 operated to deliver power from the generator 20. A bypass switch 50 is operative to bypass the UPS 40, and may be used, for example, to maintain power to the PDU in the event of a failure of the UPS 40 or a deactivation of the UPS 40 for maintenance operations.
Data centers are commonly designed according to Tier specifications defined by the Uptime Institute (www.uptimeinstitute.org). These specifications generally require a power distribution system with significant redundancy. For example, Tier II data centers are equipped with redundant UPS systems, while Tier IV data centers require redundant input power lines with redundant UPS systems for each input power line. Statistics show, however, that even these highly redundant arrangements are vulnerable to catastrophic failures due to, for example, human error or equipment malfunctions.